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MEDIUM

Mozilla: CSS sanitization does not escape HTML tags

Published Jan 8, 2020

Description

When pasting a &lt;style&gt; tag from the clipboard into a rich text editor, the CSS sanitizer does not escape &lt; and &gt; characters. Because the resulting string is pasted directly into the text node of the element this does not result in a direct injection into the webpage; however, if a webpage subsequently copies the node's innerHTML, assigning it to another innerHTML, this would result in an XSS vulnerability. Two WYSIWYG editors were identified with this behavior, more may exist. This vulnerability affects Firefox ESR < 68.4 and Firefox < 72.

Affected products

Remediation

No remediation recorded yet.

Metrics

References (30)

Change history (0)

No recorded changes yet.

Sources
CVE.org / MITRE
Status PUBLISHED
Assigner mozilla
Published Jan 8, 2020
Updated Aug 5, 2024
Reserved Sep 30, 2019
NVD
Status Modified
Modified Jun 17, 2026
Red Hat
Severity Moderate
Public date Jan 7, 2020